TITLE: GCN CIRCULAR NUMBER: 10263 SUBJECT: GRB 091208B: Gemini-North redshift DATE: 09/12/08 15:09:46 GMT FROM: Klaas Wiersema at U of Leicester K. Wiersema, N. R. Tanvir (U. Leicester), A. Cucchiara (PSU), A. J. Levan (U. Warwick) & D. Fox (PSU) report: We observed the afterglow of GRB 091208B (Pagani et al. GCN 10256; de Ugarte Postigo et al. GCN 10255) with the GMOS-N spectrograph on Gemini North, beginning at 11:17 UT on December 8. We use the R400 grism. The resulting spectrum covers the wavelength range 4000-8400 A and shows clear absorption lines of the MgII doublet (2796,2803), MgI (2853), FeI (2967), FeII (2586,2600) and MnII (2576,2594,2606) at a common redshift of z = 1.063. We thank the Gemini-N staff, in particular K. Chiboucas, for performing this observation.